This invention is directed to a valve actuating mechanism which includes valve position indicating means and deactivating means responsive to valve malfunction.
Heretofore, rotary valves, such as ball valves or the like, have been driven by rotary motors through drive train means which include spur, sun and planatary gears leading to a rotatable clutch housing. A clutch ring is carried by the rotatable clutch housing and is effective to drive an output shaft leading to the rotary valve. The output shaft is fixed for rotation with a moving means which is rotatable relative to the clutch housing. A rotatable member engages and moves a valve position indicator between angular stop positions. When the indicator reaches one of its stop positions, e.g. indicating open and closed positions of the valve, the indicator prohibits further movement of the rotatable member. The rotatable member, in turn, engages the clutch ring to disengage the clutch ring from the rotatable clutch housing and thereby deactivate the drive train. The valve position indicator also is connected through electrical switch means to the drive motor to shut-down the motor once the valve reaches one of its positions.
With such valve actuating mechanisms and valve position indicating means of the prior art, the position indicating means, i.e. position indicator switches, actually indicate actuator position and not the valve position. In other words, valve failure would not be detected by the position indicator switches because of their typical location in conjunction with the actuator. Most failures experienced were in the connection joint between the actuator and the valve. Since the position indicating switches were operative in conjunction with the actuator, failure of the valve itself was not indicated.
Attempts have been made to solve this problem by mounting position indicating switches directly on the valve. However, this approach requires running electrical wires externally from the valve to the actuator. Such wires are vulnerable to damage. Other attempts have been made to add an additional connector which significantly adds to the cost and weight of the mechanism.
The present invention is directed to providing a new and improved valve actuating mechanism, which may include valve position indicating means, and including override means in the output connection to the valve to deactivate the power means and valve position indicating means responsive to valve malfunction.